North Carolina Counties with 8-Hour Ozone Violations 2006-2008
In March 2008, the US EPA promulgated a revision of the ozone standard with a lower nonattainment threshold. We have colored the Design Value map in a novel way so that it can be compared easily to past years with the previous standard and to future years with the new standard. We present the details in four tables. Table 1 and Table 2 refer to the ozone standard that was effective from 1997 through 2007. Table 3 and Table 4 refer to the ozone standard that was effective beginning in 2008.
Table 1. The following table shows two counties with a 3-year average of the annual 4th high value for each year equaling 0.085 ppm level or higher (violation of the 8-hour standard that was in effect from 1997 through 2007). The first column lists the county; the second lists the average value for that county. On the 2006-2008 Design Value Map, these counties are colored red.
| County | Average value |
|---|---|
| Mecklenburg | 0.094 ppm |
| Rowan | 0.088 ppm |
Table 2. The following table shows 27 monitored counties that are attaining the 0.085 ppm standard that was in effect from 1997 through 2007. The first column lists the county; the second lists the average value for that county. On the 2006-2008 Design Value Map, these counties are colored orange and green, with orange signifying counties that would not attain the 2008 8-hour standard.
| County | Average Value |
|---|---|
| Alexander | 0.077 ppm |
| Avery | 0.068 ppm |
| Buncombe | 0.071 ppm |
| Caldwell | 0.075 ppm |
| Caswell | 0.079 ppm |
| Chatham | 0.072 ppm |
| Cumberland | 0.077 ppm |
| Davie | 0.082 ppm |
| Durham | 0.078 ppm |
| Edgecombe | 0.076 ppm |
| Forsyth | 0.081 ppm |
| Franklin | 0.077 ppm |
| Graham | 0.078 ppm |
| Granville | 0.080 ppm |
| Guilford | 0.082 ppm |
| Haywood | 0.078 ppm |
| Johnston | 0.075 ppm |
| Lenoir | 0.074 ppm |
| Lincoln | 0.082 ppm |
| Martin | 0.073 ppm |
| New Hanover | 0.069 ppm |
| Person | 0.077 ppm |
| Rockingham | 0.080 ppm |
| Swain | 0.065 ppm |
| Union | 0.080 ppm |
| Wake | 0.080 ppm |
| Yancey | 0.077 ppm |
Table 3. The following table shows 20 counties with a 3-year average of the annual 4th high value for each year equaling 0.076 ppm level or higher (violation of the 8-hour standard established in 2008). The first column lists the county; the second lists the average value for that county. On the 2006-2008 Design Value Map, these counties are colored red and orange, with red signifying counties that violated the 1997 8-hour standard and orange signifying counties attaining the 1997 8-hour standard.
| County | Average Value |
|---|---|
| Alexander | 0.077 ppm |
| Caswell | 0.079 ppm |
| Cumberland | 0.077 ppm |
| Davie | 0.082 ppm |
| Durham | 0.078 ppm |
| Edgecombe | 0.076 ppm |
| Forsyth | 0.081 ppm |
| Franklin | 0.077 ppm |
| Graham | 0.078 ppm |
| Granville | 0.080 ppm |
| Guilford | 0.082 ppm |
| Haywood | 0.078 ppm |
| Lincoln | 0.082 ppm |
| Mecklenburg | 0.094 ppm |
| Person | 0.077 ppm |
| Rockingham | 0.080 ppm |
| Rowan | 0.088 ppm |
| Union | 0.080 ppm |
| Wake | 0.080 ppm |
| Yancey | 0.077 ppm |
Table 4. The following table shows 9 monitored counties that are attaining the 0.076 ppm standard that was established in 2008. The first column lists the county; the second lists the average value for that county. On the 2006-2008 Design Value Map, these counties are colored green.
| County | Average Value |
|---|---|
| Avery | 0.068 ppm |
| Buncombe | 0.071 ppm |
| Caldwell | 0.075 ppm |
| Chatham | 0.072 ppm |
| Johnston | 0.075 ppm |
| Lenoir | 0.074 ppm |
| Martin | 0.073 ppm |
| New Hanover | 0.069 ppm |
| Swain | 0.065 ppm |
Note:
- Additional counties may be involved in emission reduction strategies
- Nonattainment designations may not follow county boundaries
- Final data validation is not yet complete